ACC Eliminates Environmental Reviews for Most New Methane Gas Plants

Phoenix, AZ – In a 4 to 1 vote, today the Arizona Corporation Commission (ACC) reversed a decision by the Arizona Power Plant and Line Siting Committee in April that required utility Unisource Electric (UNSE) to obtain a certificate of environmental compatibility (CEC) for its planned 200 MW expansion of its Black Mountain Generating Station in Mohave County. The ACC’s decision now exempts UNSE from obtaining a CEC for the project. This sets a harmful precedent by allowing gas-fired power plants to bypass environmental review. It allows utilities a loophole to forgo review of their environmental impacts during a dangerously hot summer season, and comes at a time when scientists have called for emissions reductions to avoid catastrophic climate change.

In its proposal shared in March, UNSE planned for the construction of 200 MWs of new methane gas at its Black Mountain Generating Station. But UNSE asserted that the ACC did not have jurisdiction over the project, arguing that the Company does not need a CEC for the four-turbine expansion project because it should be considered four separate 50 MW power plants rather than one 200-MW power plant. UNSE’s unprecedented interpretation of the Power Plant Siting Statute exempts all new gas peaking plants from a regulatory process meant to evaluate their environmental impacts and their need, and removes regulatory authority from the Commission for Arizona’s new peaking gas plants. 

During the ACC’s open meeting, Sierra Club and other Intervenors called on the Commission to uphold the Power Plant and Line Siting Committee’s order, making clear that approving UNSE’s new interpretation of the Siting Statute would overturn decades of Commission precedent. Members of the public voiced concerns over the project’s harmful impacts and the need for continued environmental reviews. 

“The ACC’s decision today enables utilities to avoid environmental compliance and continue to write their own rules that often go against the best interests of ratepayers, and the planet,” said Sierra Club Grand Canyon Chapter Director, Sandy Bahr. “UNSE proposed a loophole that would allow it and other utilities to avoid Certificate of Environmental Compatibility requirements and the ACC stamped it with its seal of approval. This disappointing decision will only result in the doubling down of dirty energy without proper consideration of the harmful impacts or any mitigation of those impacts.” 

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